1. Field of the Invention
The present invention relates to a discharge device for discharging a medium, such as recording paper for which recording is performed, by rotation of a discharge-driving roller, and a liquid emitting apparatus including the above discharge device, such as an ink-jet type recording apparatus.
The term “liquid emitting apparatus” is used for referring not only to a recording apparatus, such as a printer, a copier and a facsimile machine, having an ink-jet type recording head for emitting ink from the recording head so as to perform recording on a recording medium but also to an apparatus that causes liquid to adhere onto a medium, corresponding to the recording medium in the above recording apparatus, by emitting the liquid selected depending on the use of the apparatus in place of the ink toward the medium from a liquid emitting head corresponding to the recording head in the above recording apparatus.
As the liquid emitting head, the following heads can be considered other than the above recording head: a color-material emitting head used for fabrication of a color filter for a liquid crystal display or the like, an electrode-material (conductive paste) emitting head used for forming an electrode in an organic EL display or a field-emission display (FED), a bioorganic compound emitting head used for fabrication of a bio-chip and a sample spraying head as a precision pipette.
2. Description of the Related Art
In order to describe a liquid emitting apparatus, an ink-jet type recording apparatus (hereinafter, referred to as a “printer”) and a compact disc (hereinafter, simply referred to as a “CD”) are described as an example of the liquid emitting apparatus and a medium onto which the liquid is emitted or a medium for which the recording is performed. Some printers can emit drops of ink, that is in form of liquid, directly onto a surface of the CD (labeled surface) opposite to a surface thereof on which digital data was recorded, thereby performing the printing operation. In this case, in order to transfer the CD along a transfer path in the printer, the CD is placed in an exclusive tray for transfer (hereinafter, simply referred to as a “carrying tray”) because the CD is a small circular disk. The CD is subjected to the printing operation while being placed in the carrying tray.
In a certain type of printer, a discharge roller of the printer, that is arranged to discharge paper or printing medium out of the printer, is formed by a discharge-driving roller, that is driven to rotate so as to discharge the printed medium, and a discharge-driven roller, that is in resilient contact with the discharge-driving roller so as to be rotated by the discharge-driving roller. The driven roller may be a toothed roller that is arranged to be brought in point-contact with the recorded surface of the recorded medium by teeth. In such a printer, when the toothed roller is brought into contact with the recorded surface of the CD as the recorded medium while the CD is pressed, a data storage area of the CD in which data was stored, that is positioned directly below the recorded surface, may be damaged. Thus, in order to prevent the aforementioned problem, it is necessary to arrange the discharge roller of the printer so as to allow the toothed roller to be moved to a non-contact position where the toothed roller is not in contact with the driving roller of the discharge roller during the printing for the CD, thereby preventing the contact of the toothed roller with the recorded surface of the CD. Therefore, a discharge frame to which the toothed roller is attached is arranged to be changeable between a contact posture in which the toothed roller is in contact with the discharge-driving roller and a non-contact posture in which the toothed roller and the discharge-driving roller are away from each other.
According to conventional techniques, a mechanism for changing the posture of the discharge frame between contact and release postures is achieved by an operation lever and a link mechanism that links a switching operation by the operation lever to the change of the posture of the discharge frame (for example, described in Japanese Patent Application Laid-Open No. 2002-192782).
The above-mentioned conventional arrangement, however, becomes complicated because the operation lever and the link mechanism are included, thereby increasing the number of parts of the arrangement and the cost. Moreover, precision of the moving amount of the toothed roller is low because the toothed roller is moved by the operation lever and the link mechanism. In some cases, the toothed roller is brought in contact with the recording surface of the CD although the data storage area of the CD is not broken.